Distributed Directory Service And Its Information System Applications

A directory can be regarded as a kind of database for a special purpose. Different fromcommon used rational databases, it stores data like a tree. The data in a directory is objectorientated and can be searched with a very high speed. A directory is usually used to store alarge amount of simple and basic data, such as network devices and users. In an informationsystem based on Internet, basic information of all the objects within the system is very criticalto keep the system run smoothly. But in common cases, this information is always distributedin different sub-systems. How to obtain formulated system-wide basic information is animportant theme of designing a large-scale information system. Lightweight Directory AccessProtocal (LDAP) based on TCP/IP protocal stack This article analyzes the speciality and advantages of LDAP and designs a frame ofLDAP service in a large-scale information system, in which the information of users anddevices is managed centrally. Then the development of LDAP-enabled application isintroduced, such as email system, whitepage service. The topics discussed are naming space,information model, data model, directory distribution and application development. Themethod of designing platform, data object, logical spacing, physical distribution and safestrategy are covered. An example, Liaohe Oilfield Comprehensive Information DirectoryService, LOCIDS, is introduced. Based on LDAP, a centralized platform of user identity, user certificate and otherapplication of information system become possible. The application developed on the base ofLDAP, such as large-scale email system, white page system, will compose an effectiveinformation system. The contents of this article cover several aspects of designing and deploying directoryservices in a large distributed information system. It has wide significance and applied valueto large enterprises, government and other organizations.